1. Field of the Invention
The present invention relates generally to tracked vehicles. More particularly, the present invention relates to a tracked bicycle for use on snow, sand, mud, etc.
2. Related Art
Mountain biking, off-road bicycling, and/or bicycling in and around nature have become popular sports or pastimes. Bikers or cyclists often enjoy riding in wilderness or natural environments, such as the woods, sand dunes, red-rocks, etc. Such environments can provide a welcome change from city or suburban environments. In addition, such environments can provide unique and challenging riding conditions, including steep uphill climbs, steep downhill descents, sharp curves, etc. Some wilderness or natural environments are provided with bike trails. Such trails can be simple paths in the dirt or sand, while others can be graded or covered with gravel, while still others may be paved. Another unique and challenging riding condition of the wilderness or natural environments is obstacles, such as larger rocks, fallen tree trunks, streams and rivers, mud, sand dunes, etc. These natural conditions provide additional enjoyment and challenge to the cycling experience.
Such bicycling or cycling is often dependent on weather conditions, or seasons. While some areas or locations allow for year-round riding, other areas can be limited to the spring, summer and fall months. For example, many popular riding areas are located in the mountains, where annual winter snowfall prohibits riding off-road or on non-maintained trails. In addition, it will be appreciated that most maintained roads are for motor vehicles, and that sharing a road with such motor vehicles in winter conditions can be extremely dangerous. Therefore, even the most ardent mountain bikers tend to store their bikes for the winter and opt for either in-door stationary bicycles, alternative winter sports such as snowshoeing or cross-country skiing, or simple waiting out the winter.
Some efforts have been made to continue mountain biking in the winter. For example, bicycles have been proposed with “fat” or wide tires to prevent sinking into the snow. Such bicycles have special, wide frames to accommodate the fat or wide tires. Thus, the rider must invest in another bicycle with this approach. As another example, standard mountain bikes have been proposed with special tires that have spikes or studs. Such tires tend to be thin enough to sink into the snow. As a further example, devices have been proposed with a seat disposed on front and rear skis. Such devices, however, are suitable only for coasting down a slope, and are not provided with any means of propulsion.
Various tracked, off-road, recreational vehicles have been proposed. Such vehicles have a continuous track, similar to tank tracks, as opposed to, or in addition to, wheels. While some tracks have been used for motor powered vehicles, such as all-terrain-vehicles (ATVs), it is not readily apparent how to adapt such tracks for use with human-powered vehicles, such as bicycles. Some tracks have been proposed for use with human-powered vehicles, but are cumbersome, awkward, and require special modifications to the bicycle.
In addition, other areas or locations have riding conditions for which typical mountain bikes are ill suited. For example, mud and sand can be as difficult to ride in as snow. Tires tend to slip and spin in both mud and sand. In addition, the tires can sink into both mud and sand.